Lens Hood - Ridges on the inside

[phillHYYUN]

I want to create a parametric lens hood design. It is basically a tube so should be simple. I am splitting the tube into three elements. First is the connecting section. This is simple. Then there is the middle section. This is a section that is just a tube. I will hopefully be able to add parameters for its length and diameter. All simple stuff. Where I am struggling is I want to add a ridged surface on the inside to prevent light reflections. Traditionally this is a series of ridges running around the inside of the tube. What is the best way of achieving this so whatever the height and diameter set in the parameters, the ridges remain consistent.,

[davebYYPCU]

If you change the tube diameter, will the number of ridges remain static and get the change in shape accommodated or will the shape remain static and the circular pattern count will adjust?

[phillHYYUN]

The ridges will run the circumference of the tube. They will remain the same size. Think like a fine scoring on the inside of the tube that will remain whatever diameter of the tube. The size and shape to remain the same, just increase in number with the length of the tube. Attached is the tube element so far and where I got stuck.

If you look at the following link, you will see similar ridges on the inside of this lens hood - https://www.amazon.co.uk/Andoer-Aluminum-Camera-Compatible-Cameras/dp/B0CHRRPT29/ref=asc_df_B0CHRRPT...

[TheCADWhisperer]

@phillHYYUN 

See Attached.

Do you need help with the parametric formula for number of instances based on length?

[phillHYYUN]

Any help would be appreciated. I am just 2 weeks into learning Fusion (any CAD really) as it was about time I actually put some effort into designing my own models. It is a steep learning curve but I am enjoying it a lot. So looking at your model, how did you achieve that?

[phillHYYUN]

Many thanks for your help on this. Here is what I have come up with so far. A simple design of a body made of three parts. The centre part is the element you did the ridges for, it took me a lot of head scratching to understand that as I am very new to this. The TPU section is the front of the lens hood. I made it from TPU for impact resistance etc. The final element is not shown in this. It is a simple ring that closes up on the front of a lens using a screw to compress it into place. The bumps in the back of the lens hood lock into this in a bayonet style of attachment. SO once the ring is attached, fitting and removal of the hood is push on and twist to lock into place.

I am sure I have made all the newbie mistakes in my design, but it does seem to work well. The OEM lens hoods only come in one length and cost up to £800. So you can understand the desire for shorter ones that can be 3D printed as needed, and at a fraction of the cost. Once I have fully tested the connection ring and the hood in different lengths and diameters I will slap it on Printables.

[TheCADWhisperer]

@phillHYYUN 

Check back - need to clean this up.

Move (as used by beginners) is almost always the wrong move.

You have too many bodies (some intersecting).

[phillHYYUN]

What should be used instead of move/copy?

[TheCADWhisperer]

@phillHYYUN 

What is the purpose of Plane2 that you created?

Isn't it the same as the XZ Plane?

[TheCADWhisperer]

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@phillHYYUN wrote:

What should be used instead of move/copy?

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@phillHYYUN 

In this case Circular Pattern.

[TheCADWhisperer]

@phillHYYUN 

What is this component?

It interferes with TPUfront

and TPUfront is 2 bodies when I would have expected that to be 1 body?

[phillHYYUN]

I think that was a mistake. I was trying to achieve something and screwed up.

[phillHYYUN]

The idea of TPUfront was simply a ring with 2 extrudes, one either side of the main lens hood. I must admit I really struggled there. I thought I should create a new component as it was a separate part of the assembly to be printed in TPU instead of PCTG which is what the main hood part is in. For some reason I struggled therein creating what should have been a very simple element.

[TheCADWhisperer]

@phillHYYUN 

Step through the attached Timeline step-by-step.

Next, we can add parameters for length (and diameter if needed).

Observe the brevity of the Timeline operations.

We could have done as one sketch if desired, but it is usually best to keep sketches simple.

[phillHYYUN]

Many thanks for that and sorry for the delay in responding. I have suddenly encountered a few medical issues that needed urgent attention. On the plus side it will mean a period stuck at home so I can start to get my head around this tool. I really appreciate the effort you have put in and will spend next week going over all you have done. I can see I have a lot to learn but this has really helped my understanding of Fusion360 and the ideas of design.